Good news for RCABS enthusiasts. RCABS air pumps are now available from a U.S. manufacturer. They are new, current models, and work well for our purposes. They are slightly larger(1/8" diameter and 1/2" overall length) than the unavailable, current Oken model, but they only cost $5.25 each, plus shipping costs. The manufacturer's contact info is:Smart Products, Inc. 1710 Ringwood Ave. San Jose, CA 95131Tel: 408 436-0740. www.smartproducts.comThe model # is AP-3PO1 It is their 6VDC 460ma @ 300 mmHg Micro air pump.The pumps should work well in Dave Welch's experimenter's kits, or in your own version of RCABS. Good luck, and have fun making your own ballast system.Art

would the smaller air pumps work like the AP-2P01 work?. i know the voltage is less, the pump volume and pressure is less, but is it enough? 65mmx25mm vs. 40mmx21mm is a significant difference in tiny subs...

Petn7The smaller pump should work fine with a micro bladder, for a small sub.

I have posted a picture of the slightly larger, AP-3PO1, inexpensive new pump, at the end of the photos on my webpage: http://www.subcommittee.com/SubComm....erID=45 Click on last photo to enlarge, and compare the Smart Products model to the unavailable Oken pump.